Engines utilize fuel injectors to introduce fuel into the combustion chambers of the engine. Although there exist fuel systems and fuel injectors of various types, fuel injectors typically utilize valves that are actuated in any of a number of different ways. For example, fuel injectors and their associated valves may be actuated mechanically, hydraulically, electronically, or using a combination of different actuation means. A specific type of valve actuator that may be used in fuel injectors is a solenoid actuated valve. The solenoid may include a solenoid coil, which acts as a magnet when provided with current, an armature, and a biasing spring. When the solenoid coil is energized, the armature is drawn toward the solenoid coil, and the valve member is moved toward or away from a valve seat. The biasing spring assists in returning the valve member to a seated position. These solenoid actuated valves may be particularly useful in accurately injecting different volumes of fuel in a broad range at precise timings in a limited spatial envelope.
Repeated contact between valve actuator assembly components during operation of the fuel injector may result in component wear that can impact performance of the fuel injector. For example, such wear may result in a gap between the valve member and valve seat and, eventually, result in failure of the fuel injector. To reduce valve wear, U.S. Pat. No. 6,752,332 to Terakado et al. suggests forming a surface reforming layer, such as a nitrided layer, having wear resistance on a surface of worn portions of the fuel injector. Such worn portions may include the valve body, valve seat, and stopper. Although the surface reforming layer of the Terakado et al. reference may be useful in some applications, it should be appreciated that a continuing need exists for improving performance of valve actuator assemblies and/or extending the useful life of such components.
The present disclosure is directed to one or more of the problems or issues set forth above.